DESCRIPTION
Isotech Semi-Standard Platinum Resistance Thermometers are designed for applications requiring high accuracy, good long-term stability and greater robustness than a traditional Standard Platinum Resistance Thermometer (SPRT). They are suitable for both laboratory and field use, including as working standards in dry blocks and liquid baths, or as high-accuracy sensors used with precision temperature readouts.
All models are metal sheathed, making them less fragile and more practical for routine calibration work than laboratory SPRTs, while still offering excellent measurement performance.
Each thermometer uses a handmade, coil-wound Pt100 platinum sensing element selected for high accuracy, low drift and long-term stability. The probes are available in a range of lengths, diameters and temperature ranges to suit different calibration applications.
Angled and 90° versions are also available for use with Isotech Portable Temperature Calibrators. These provide additional clearance where a unit under test has a terminal head or connection housing that would otherwise obstruct a straight reference thermometer. For best measurement performance, these probes should be calibrated as part of the portable calibrator system.
Isotech’s UKAS accredited laboratory can calibrate Semi-Standard PRTs to low uncertainties across their operating range. The calibration should be selected to suit the required temperature range, measurement uncertainty and application, and Isotech can advise on the most appropriate calibration service.
SPECIFICATION
| Technical Feature | Value |
|---|---|
| Ro | 100Ω ± 0.05Ω |
| Alpha | 0.003850 ± 0.000005 |
| Standard | IEC 60751 |
| Stability | 0.010Ω/ year |
| Recommended Current | 1mA |
| Self Heating at 1mA | 0.004°C |
| Calibration | Optional UKAS Calibration at extra cost. See table for typical uncertainties. |
| Connection | 4 Wire |
| Max. Handle Temperature | 80°C |
Model Types
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| Model | Temperature Range | Sheath Diameter | Sheath Length | Sensing Length | Handle |
|---|---|---|---|---|---|
| General Purpose | |||||
| 935-14-61 | −50°C to 250°C | 4 mm | 300 mm | 6 mm | 19 × 120 mm |
| 935-14-112 | −50°C to 450°C | 4 mm | 300 mm | 6 mm | No Handle |
| 935-14-98 | −50°C to 350°C | 4 mm | 300 mm | 8 mm | No handle |
| 935-14-116 | −100°C to 450°C | 6 mm | 350 mm | 25 mm | 19 × 120 mm |
| 935-14-98 | −50°C to 350°C | 4 mm | 300 mm | 8 mm | No handle |
| Low Temperature PRTs | |||||
| 935-14-115 | −196°C to 100°C | 4 mm | 300 mm | 8 mm | Ø 17.5 mm |
| 935-14-13 | −196°C to 250°C | 6 mm | 350 mm | 25 mm | 25 × 115 mm |
| 935-14-113 | −100°C to 250°C | 6 mm | 350 mm | 25 mm | 19 × 120 mm |
| High Temperature PRTs | |||||
| 935-14-72 | −50°C to 670°C | 6 mm | 375 mm | 25 mm | No handle |
| Laboratory Working Standards | |||||
| Longer probes designed primarily for laboratory use. The low- and high-temperature models can be used as a complementary pair where coverage from −200°C to 660°C is required. | |||||
| 935-14-95L | −200°C to 165°C | 6 mm | 480 mm | 25 mm | 25 × 115 mm |
| 935-14-95H | −80°C to 670°C | 6 mm | 480 mm | 25 mm | 19 × 120 mm |
| Angled Probes | |||||
| 935-14-82 | −50°C to 250°C | 4 mm | 165 mm | 6 mm | Angled |
| 935-14-85 | −50°C to 250°C | 6 mm | 385 mm | 25 mm | Angled |
| 935-14-75 | −50°C to 250°C | 4 mm | 213 mm | 6 mm | 90° |
| 935-14-79 | 0°C to 660°C | 6 mm | 199 mm | 25 mm | 90° |
Typical Uncertainties with Optional UKAS Calibration
| Temperature | 935-14-95L | 935-14-61 | 935-14-13 | 935-14-16 935-14-116 |
935-14-95H 935-14-72 |
|---|---|---|---|---|---|
| −196°C | 25 mK | N/A | 25 mK | N/A | N/A |
| −80°C | 20 mK | N/A | 20 mK | 25 mK | 25 mK |
| −50°C | 15 mK | 15 mK | 15 mK | 20 mK | 20 mK |
| 0°C | 10 mK | 10 mK | 10 mK | 15 mK | 15 mK |
| 50°C | 10 mK | 10 mK | 10 mK | 15 mK | 15 mK |
| 156°C | 10 mK | 10 mK | 10 mK | 20 mK | 20 mK |
| 232°C | N/A | 15 mK | 15 mK | 25 mK | 25 mK |
| 420°C | N/A | N/A | N/A | 40 mK | 40 mK |
| 550°C | N/A | N/A | N/A | N/A | 50 mK |
| 660°C | N/A | N/A | N/A | N/A | 50 mK |
Typical Uncertainties with Optional Isotech UKAS Accredited Calibration, k = 2.
The above uncertainties do not include long-term drift.
Typical stability of a correctly used Semi-Standard PRT is 0.01°C/year at 0°C.
The actual uncertainty of an individual probe is determined at the time of calibration.
Downloads
Semi Standard PRTS
High-stability reference thermometers for laboratory and field calibration.
Isotech Semi-Standard Platinum Resistance Thermometers are high-stability reference probes designed for laboratory and field calibration. They are ideal for use as working standards in dry blocks and liquid baths, or as high-accuracy sensors with precision readouts such as the Isotech milliK.
- High accuracy from −200°C to 670°C
- Working standards for dry blocks and liquid baths
- Straight and angled models for laboratory and field use
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